Speed Calculator

[aqwut]

I wonder if there's any way to figure out how many watt/lbs we need to go a certain speed?.. that would be Freakin' awesome..... I don't know if I'm sayin' it right, but you' know what I mean....

[BrianG]

Yeah, the trouble is getting that spec from all the different motor manufacturers. This is more generic and gained from experience and reading these forums, but probably not as accurate.

[Dafni]

Maybe I can have a word with Mr Lehner about this. When he's in the right mood, he's very helpful ;)

But the weight/size thing looks good, Brain. From my experience it makes sense.

[BrianG]

Originally Posted by Dafni

Maybe I can have a word with Mr Lehner about this. When he's in the right mood, he's very helpful ;)

That would be great! I want to make this tool as accurate and easy to use as possible. Boy, it sure has changed from version 1!

So, you don't think there should be some overlap for the other motors?

[Nick]

It reccomends me a 6XL for 6s on a 14lb truck. To do upto 60mph.

[Dafni]

6XL on 6S should give you a High RPM Warning.

Overlap for motors, why not? With something like a good choice/better choice note?

[BrianG]

Originally Posted by Nick

It reccomends me a 6XL for 6s on a 14lb truck. To do upto 60mph.

Oops! I guess I forgot to implement warnings for the calculated values!

[coolhandcountry]

Are friend Mr. Promod did some testing on watts per speed. It took about 2000 watts for an emaxx to hi 60 mph. That was with a 2240 and lehner xl motor.

[Promod]

Must of the smaller motors I've tested will pull great watts(even more than a large motor) but will not run the speed of a larger motor. So watts don't tell the whole story.
My 2240/10 on 6S pulled around 2200 watts to run 60 mph. The 2240/12 on 9S made 3300 watts. Never did a speed test with the 9s but would think it would run close to 70 mph if the truck would stay on the ground:027: .

Thank you,
Promod

[Serum]

Barry, have you ever seen this graph of the lehner 1950?

http://lehner-motoren.com/motordaten...50-6HA.32V.xls

[coolhandcountry]

I noticed you got a 1st and 2nd gear to a savage.

What about the 1st 2nd and 3rd on a 3 speed savage?

[BrianG]

I can add that. What's the 3rd gear ratio? Actually I need the tooth count, not the ratio. This allows me to maintain the highest precision possible.

In the 3-speed, does first and/or second gear change as well, or do they just add a third gear?

[coolhandcountry]

first is lower by 10%. 2nd is lower than 2 speed 2nd. 3rd is 10% higher. I am not sure on tooth count. I did know one time. Rene may have it handy.

[Serum]

Not a problem;

(going fron the wheels to the motor)

Diff is 43/13
outputshaft 30/31 (gear on the outputshaft is larger (31) than the 'drivegear' (30)
1st gear 44/18
2nd gear 41/21
3rd gear 38/24

[BrianG]

OK, new version. Added overlap of motors for a slightly wider selection of motors, added a section for adding other ratios (thanks to the Savage for having another ratio in the tranny :031:), and added the three-speed Savage ratios.

Speed Calculator